|
(11) | EP 2 416 477 A3 |
(12) | EUROPEAN PATENT APPLICATION |
|
|
|
|
|||||||||||||||||||||||
(54) | AD-DC converter and control circuit thereof |
(57) The invention discloses a control circuit for an AC-DC converter. The control circuit
includes a power control circuit for comparing an input current sensing signal generated
by sensing an input current of the AC-DC converter and a power level control input
and in response thereto generating a frequency modulation control signal, in which
the frequency modulation control signal is used to control the output power of the
AC-DC converter and suppress harmonics of the input current, and a square wave generator
connected to the power control circuit for generating a driving signal used to drive
the switch circuit of the AC-DC converter according to the frequency modulation control
signal, in which the frequency of the driving signal is varied with the frequency
modulation control signal, thereby suppressing harmonics of the input current and
regulating the switching frequency the AC-DC converter, and regulating the output
power of the AC-DC converter.
|